Target is what you should have so your target is considered as compliant, and you are at risk when you reach the "risk" level.

For example let's say you want that your target is 75% and you want to be warned if you reach 85%,put the risk at 85%.

You begin at 100%, then some stuff fail, so you go from 100% to 95%, 90%, 85%, 84%.

At 85%, you can trigger a milestone so an email is sent to warn you that you are at 85%.

When you reach 74%, you aren't compliant anymore.

Think about a Starbucks.

You have to give coffee to some guys all day long and you can drop only 10 cups of coffee. After 3 cup of coffee dropped, your manager comes and tells you to do your job properly. After 10 cups of coffee, you're fired.

So here your risk is at 3 and the milestone is the manager who kicks your ass.

The compliance is 10.

I won't do % because it's more understandable that way, but think that 100% is no cup dropped.